London Heathrow (LHR) is the busiest airport in the UK and Europe, and indeed one of the most highly patronized hubs in the entire world. Handling in the region of 80 million passengers a year, the facility serves a huge variety of airlines and destinations, with some being more far-flung than others. Next month will see an interesting selection of airlines serving routes that exceed 6,000 miles (9,656.1 km).